Inserter systems, such as those applicable for use with the present invention, are mail processing machines typically used by organizations such as banks, insurance companies and utility companies for producing a large volume of specific mailings where the contents of each mail item are directed to a particular addressee.
In many respects, the typical inserter system resembles a manufacturing assembly line. Sheets and other raw materials (other sheets, enclosures, and envelopes) enter the inserter system as inputs. Then, a variety of modules or workstations in the inserter system work cooperatively to process the sheets until a finished mail piece is produced. The exact configuration of each inserter system depends upon the needs of each particular customer or installation.
Typically, inserter systems prepare mail pieces by gathering collations of documents on a conveyor. The collations are then transported on the conveyor to an insertion station where they are automatically stuffed into envelopes. After being stuffed with the collations, the envelopes are removed from the insertion station for further processing. Such further processing may include automated closing and sealing the envelope flap, weighing the envelope, applying postage to the envelope, and finally sorting and stacking the envelopes.
The input stages of a typical inserter system are depicted in FIG. 1a. At the input end of the inserter system, rolls or stacks of continuous printed documents, called a web, are provided at a web supply and fed into a web cutter where the continuous web is cut into individual sheets. In some inserter systems, the input stages of an inserter also include a right-angle turn to allow the individual pages to change their moving direction before they are fed into the inserter system, as shown in FIG. 1b. 
FIG. 2 illustrates the input stages of an inserter wherein the continuous web material is provided in a fanfold stack. As shown in FIG. 2, the continuous web material 5 is drawn out of a fanfold stack 2. Typically, sheets in the continuous web material 5 are linked by perforations so that the web material can be driven continuously by a web driver 100 into a web-cutting module 200. The web-cutting module 200 has a cutter 210, usually in a form of a guillotine cutting blade, to cut the web material 5 crosswise into separate sheets 8.
In some inserter systems, the web material 5 must be split into two side-by-side portions by a cutting device 212 as shown in FIG. 3. The cutting device 212 may be a stationary knife or a rotating cutting disc. After the web material 5 is split into two side-by-side portions, it is cut crosswise by the cutter 210 into pairs of sheets 8I and 8II. The sheets 8I and 8II move side-by-side toward a right angle turn device so that they can move in tandem into an inserter system (not shown).
In other mailing machines, the web-material 5 has a row of sprocket holes on each side of the web material so that the web can be driven by a tractor with pins or a pair of moving belts with sprockets. As shown in FIG. 4, a pair of cutting devices 214 are used to separate the side strips containing the holes from the web material 5 before the web material is cut crosswise by the cutter 210. Additionally, some mechanical devices (not shown) are used to remove the side strips before the web-material is fed into the cutter 210.
When a new roll or stack of web material is fed into the web cutter module 200, it is essential to adjust the cutter so that the web will be split into side-by-side portions at the correct location (FIG. 3) or the side strips will be cut at the correct locations (FIG. 4).
A fanfold stack of web material is perforated at each sheet length location to facilitate folding a large number of sheets into a compact stack. It is desirable to cut off the perforated edges so that the individual cut sheets will have clear edges. Cutters with the ability to cut off the perforated edges are referred to as having the chip-out capability. The cutter 220 as shown in FIG. 5 is an illustrated example of the cutters with the chip-out capability. The chip-out portion containing the perforation between adjacent sheets is referred to as a chip. It is a small width of paper cut transversely from the web material. Blades are commonly designed to accommodate the chip-out capability in the following chip-out widths: ⅛ of an inch, 7.8 mm, 1/16 of an inch and ¼ of an inch. In the United States, the ⅛ inch chip-out is most common, whereas the 7.8 mm chip-out is most common in Europe. In a ⅛ inch chip, the width of the chip on each side of perforation is only 1/16 of an inch. In a 1/16 inch chip, the width of the chip on each side of perforation is only 1/32 of an inch. The chip-out operation requires a high web position accuracy with respect to the blade.
The chip-out cutter 220 is depicted in the figures as two separate blade plates, with the chip-out region in between. It will be appreciated by those skilled in the art that a common alternative chip-out blade is comprised of a single plate having a width corresponding to the chip-out width. The two sharpened edges of the single plate serve to cut both sides of the chip-out as the blade is lowered in a scissoring action into a corresponding slot.
It is thus advantageous and desirable to provide a method and system to establish an accurate datum for the motion control system that locates the web for subsequent cutting.